I did finally figure out how to send my comment, attached below. Apparently  you cannot do it by email but you can do it electronically. Here is a more precise guide:

1. Go to this website: http://recordsnotrevenue.com/

2. Read that page, but if you already understand the issue and simply want to register your comments, scroll down to the bottom half of the page where it says "Make your voice heard in three easy steps!"

3. Skip steps one and two and click on the Federal Rule Making Portal under Step 3.

4. Register your comment and decide if you want your contact information included (or not) and submit.

5. Collect your tracking number

6. Advice: Do NOT make your comment political (i.e., as a rebuke of the current administration, who, after all, are the people who will render the final decision).

7. Send copies of your comments to the appropriate members of your Congressional district.

My comment:

Your Comment Tracking Number: 1k3-9dsl-epo8

I have been researching and writing about my extended family for the last 25 years and have relied for much of my information on freely available files held by the National Archives and the Library of Congress. As honest taxpayers we already support our government substantially and should not be penalized for requesting copies of information that was collected with money from our taxes. In other words, charging for access to this information is a form of double taxation. One can understand a per page charge for hard copy documents, but only at a normal commercial rate of a few cents per page. Charging hundreds of dollars is unconscionable. Where those documents are already digitized, the cost of emailing them should be near zero!

Our government is supposed to be "of the people, by the people and FOR the people". We recognize that final obligation in many ways, including the maintenance of free museums in our nation's capital. Certainly the upkeep of those museums is an expensive proposition and yet we still provide free access. We do it in part because we recognize that an informed and educated citizenry is essential for our democracy to continue to prosper. I would maintain that providing free access to documents about our own families is just as important as providing free access to the tons of other documents that are readily available at the National Archives, the Library of Congress and the D.C. public museums. This is an urgent matter. Please do not let these proposed fee increases go forward. The present fee schedule is already cumbersome!